This invention relates to foamable pharmaceutical and cosmetic compositions and foams, containing aprotic polar solvents and uses.
External topical administration is an important route for the administration of drugs in disease treatment. Administration into body cavities is gaining in importance. Many groups of drugs, including, for example, antibiotic, anti-fungal, anti-inflammatory, anesthetic, analgesic, anti-allergic, corticosteroid, retinoid and anti-proliferative medications are preferably administered in creams and ointment.
There are many different types of foams and within each foam type there are many levels of qualities. For example, the froth on the head of beer, lather of shampoo, and lather of shaving cream have been loosely described as foam but all are different from one another. Such differences speak to usability applicability. At one end of the cosmetic or pharmaceutical foam spectrum, the foam can be long-lasting and not readily breakable upon mechanical stimulation like shaving foams. Such foams lack suitability for pharmaceutical use since they lather with mechanical stimulation and require washing off. At the other end of the spectrum, the foam can be quick breaking without mechanical stimulation and collapse upon release. Such foams can be inconvenient since they can disappear rapidly before they can be conveniently applied to the intended target. Yet another type of foam is delayed foaming gel which is expelled as a gel but is said to expand into a type of foam on exposure to body temperature. Such expansion can be slow or delayed and inconvenient. Foams are considered a more convenient vehicle for topical delivery of active agents. There are several types of topical foams, including aqueous foams, such as commonly available shaving foams; hydroalcoholic foams; emulsion-based foams, comprising oil and water components; and oleaginous foams, which consist of high oil content. In skin therapy, oil containing foams are preferred, since oil contributes to skin protection and moisturization, which improve the therapeutic effect of the formulation. Typically foams are made using liquefied hydrocarbon gas propellant, such as propane, butane and isobutene, or hydro-fluoro carbon propellants.
Formulations containing aprotic polar solvents, such as Dimethyl sulfoxide (“DMSO”), have been occasionally known. However, these formulations have only been known as creams, gels or liquid formulations. Yet, despite the many benefits of pharmaceutical and cosmetic foam formulations, until now DMSO-containing formulations have not been developed in a commercial foam form.